NO130638B - - Google Patents
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- NO130638B NO130638B NO695068A NO506869A NO130638B NO 130638 B NO130638 B NO 130638B NO 695068 A NO695068 A NO 695068A NO 506869 A NO506869 A NO 506869A NO 130638 B NO130638 B NO 130638B
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- Prior art keywords
- phosphate
- content
- calcined
- raw
- sodium
- Prior art date
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- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 claims description 48
- 229910019142 PO4 Inorganic materials 0.000 claims description 39
- 235000021317 phosphate Nutrition 0.000 claims description 39
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 36
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 32
- 239000000203 mixture Substances 0.000 claims description 30
- 239000010452 phosphate Substances 0.000 claims description 30
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 claims description 30
- 229910052731 fluorine Inorganic materials 0.000 claims description 26
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 21
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 claims description 18
- 239000011737 fluorine Substances 0.000 claims description 18
- 239000002994 raw material Substances 0.000 claims description 18
- 238000001354 calcination Methods 0.000 claims description 17
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 claims description 16
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 16
- 238000000034 method Methods 0.000 claims description 16
- 239000000377 silicon dioxide Substances 0.000 claims description 16
- 235000012239 silicon dioxide Nutrition 0.000 claims description 16
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 16
- 229910052681 coesite Inorganic materials 0.000 claims description 14
- 229910052906 cristobalite Inorganic materials 0.000 claims description 14
- 229910052682 stishovite Inorganic materials 0.000 claims description 14
- 229910052905 tridymite Inorganic materials 0.000 claims description 14
- KKCBUQHMOMHUOY-UHFFFAOYSA-N Na2O Inorganic materials [O-2].[Na+].[Na+] KKCBUQHMOMHUOY-UHFFFAOYSA-N 0.000 claims description 13
- 229910000029 sodium carbonate Inorganic materials 0.000 claims description 8
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims description 7
- 150000001875 compounds Chemical class 0.000 claims description 7
- 238000004519 manufacturing process Methods 0.000 claims description 7
- 239000011734 sodium Substances 0.000 claims description 7
- 229910052708 sodium Inorganic materials 0.000 claims description 7
- 239000008187 granular material Substances 0.000 claims description 6
- RYFMWSXOAZQYPI-UHFFFAOYSA-K trisodium phosphate Chemical class [Na+].[Na+].[Na+].[O-]P([O-])([O-])=O RYFMWSXOAZQYPI-UHFFFAOYSA-K 0.000 claims description 4
- 239000012467 final product Substances 0.000 claims description 3
- 239000001488 sodium phosphate Substances 0.000 claims description 3
- 235000011008 sodium phosphates Nutrition 0.000 claims description 3
- -1 sodium carbonate Chemical class 0.000 claims description 2
- 239000000047 product Substances 0.000 description 23
- 239000007789 gas Substances 0.000 description 11
- 150000003013 phosphoric acid derivatives Chemical class 0.000 description 9
- 239000000243 solution Substances 0.000 description 9
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 6
- 235000011121 sodium hydroxide Nutrition 0.000 description 6
- 239000000292 calcium oxide Substances 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- VSIIXMUUUJUKCM-UHFFFAOYSA-D pentacalcium;fluoride;triphosphate Chemical compound [F-].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O VSIIXMUUUJUKCM-UHFFFAOYSA-D 0.000 description 4
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 description 3
- 229910052586 apatite Inorganic materials 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 239000001506 calcium phosphate Substances 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 235000010205 Cola acuminata Nutrition 0.000 description 2
- 244000228088 Cola acuminata Species 0.000 description 2
- 235000015438 Cola nitida Nutrition 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- 239000007795 chemical reaction product Substances 0.000 description 2
- 230000029087 digestion Effects 0.000 description 2
- 150000002222 fluorine compounds Chemical class 0.000 description 2
- 230000004927 fusion Effects 0.000 description 2
- 239000002686 phosphate fertilizer Substances 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 229940078499 tricalcium phosphate Drugs 0.000 description 2
- 229910000391 tricalcium phosphate Inorganic materials 0.000 description 2
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N 7553-56-2 Chemical compound [I] ZCYVEMRRCGMTRW-UHFFFAOYSA-N 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- 201000004624 Dermatitis Diseases 0.000 description 1
- 241000196324 Embryophyta Species 0.000 description 1
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 239000005864 Sulphur Substances 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 230000002745 absorbent Effects 0.000 description 1
- 239000002250 absorbent Substances 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 208000010668 atopic eczema Diseases 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 description 1
- 235000011010 calcium phosphates Nutrition 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000013065 commercial product Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 238000006115 defluorination reaction Methods 0.000 description 1
- 239000011363 dried mixture Substances 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 229910052587 fluorapatite Inorganic materials 0.000 description 1
- 229940077441 fluorapatite Drugs 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000000295 fuel oil Substances 0.000 description 1
- 210000004209 hair Anatomy 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910000040 hydrogen fluoride Inorganic materials 0.000 description 1
- 238000006192 iodination reaction Methods 0.000 description 1
- 239000011630 iodine Substances 0.000 description 1
- 229910052740 iodine Inorganic materials 0.000 description 1
- 238000009533 lab test Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 229910052585 phosphate mineral Inorganic materials 0.000 description 1
- 239000002367 phosphate rock Substances 0.000 description 1
- OJMIONKXNSYLSR-UHFFFAOYSA-N phosphorous acid Chemical compound OP(O)O OJMIONKXNSYLSR-UHFFFAOYSA-N 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 150000003388 sodium compounds Chemical class 0.000 description 1
- 229910001948 sodium oxide Inorganic materials 0.000 description 1
- 229910052938 sodium sulfate Inorganic materials 0.000 description 1
- 235000011152 sodium sulphate Nutrition 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- QORWJWZARLRLPR-UHFFFAOYSA-H tricalcium bis(phosphate) Chemical class [Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O QORWJWZARLRLPR-UHFFFAOYSA-H 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 238000010626 work up procedure Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B25/00—Phosphorus; Compounds thereof
- C01B25/16—Oxyacids of phosphorus; Salts thereof
- C01B25/26—Phosphates
- C01B25/45—Phosphates containing plural metal, or metal and ammonium
-
- C—CHEMISTRY; METALLURGY
- C05—FERTILISERS; MANUFACTURE THEREOF
- C05B—PHOSPHATIC FERTILISERS
- C05B13/00—Fertilisers produced by pyrogenic processes from phosphatic materials
- C05B13/02—Fertilisers produced by pyrogenic processes from phosphatic materials from rock phosphates
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Compositions Of Oxide Ceramics (AREA)
- Fertilizers (AREA)
- Fodder In General (AREA)
Description
Fremgangsmåte ved fremstilling av kalsinert Procedure for the production of calcined
fosfat med lavt fluorinnhold. phosphate with a low fluoride content.
Oppfinnelsen angår en fremgangsmåte ved fremstilling av kalsinert fosfat med lavt fluorinnhold og hoy opploselighet i sitronsyre og tilsvarende formelen Ca (P0^)2* CaNaPO^, ved kalsinering av en blanding av råfosfat, fosforsyre og en natriumoxyddannende forbindelse, som natriumcarbonat,- en konsentrert natriumhydroxydopplosning eller blandinger derav, ved en temperatur over ca. 1200°C i nærvær av vanndamp, og fremgangsmåten er særpreget ved at det anvendes et råfosfat med et SiO^-innhold av under 2 vekt% som granuleres med en slik mengde av fosforsyre og en natriumoxyddannende forbindelse hhv. av natriumfosfater at sluttproduktet får et molforhold Ca0:Na20:P20j av 8:1:3, hvoretter granulatet torkes og kalsineres ved en temperatur av 1350-l550°C. The invention relates to a process for the production of calcined phosphate with a low fluorine content and high solubility in citric acid and corresponding to the formula Ca (P0^)2* CaNaPO^, by calcining a mixture of crude phosphate, phosphoric acid and a sodium oxide-forming compound, such as sodium carbonate, - a concentrated sodium hydroxide solution or mixtures thereof, at a temperature above approx. 1200°C in the presence of water vapour, and the method is characterized by the use of a raw phosphate with a SiO^ content of less than 2% by weight which is granulated with such an amount of phosphoric acid and a sodium oxide-forming compound or of sodium phosphates that the final product has a molar ratio Ca0:Na20:P20j of 8:1:3, after which the granules are dried and calcined at a temperature of 1350-1550°C.
Forskjellige fremgangsmåter er blitt foreslått for fremstilling av kalsinerte fosfater med lavt fluorinnhold fra naturlig fore-kommende kalsiumfosfater som. i alminnelighet inneholder 3-<i>+,2% Various methods have been proposed for the production of calcined phosphates with a low fluorine content from naturally occurring calcium phosphates such as generally contains 3-<i>+.2%
fluor og hovedsakelig består av fluorapatitt,og hvor natriumcarbonat og fosforsyre hhv. natriumfosfater anvendes som'oppslutningsraiddel. Fra eldre patentskrifter, f.eks. de tyske patentskrifter nr.730578, nr. 729909, nr. 730771 eller nr. 7M+999,- fremgår det at det ved gjennomføring av slike prosesser betraktes som viktig at Si02~innholdet i det produkt -som kalsineres, skal være ca. h vekt% eller derover. Det er også angitt i tysk. patentskrift nr. 1062259 at et hoyt siliciumdioxydinnhold i råmaterialblandingen er nodvendig. Ifolge dette patentskrift fremstilles sintret fosfatgjodning ved fluoride and mainly consists of fluorapatite, and where sodium carbonate and phosphoric acid respectively sodium phosphates are used as a digestion agent. From older patent documents, e.g. the German patent documents no. 730578, no. 729909, no. 730771 or no. 7M+999, - it appears that when carrying out such processes it is considered important that the Si02~ content in the product -which is calcined, should be approx. h wt% or more. It is also indicated in German. patent document no. 1062259 that a high silicon dioxide content in the raw material mixture is necessary. According to this patent document, sintered phosphate fertilizer is produced by
at det til råfosfat tilsettes ca. 0, 5-^% natrium i form av primært eller sekundært natriumortofosfat, tilsvarende 1-2 mol natrium pr. mol fluorbundet kalsium, og denne blanding kalsineres i nærvær av vanndamp- ved en temperatur over 1150°C, og det kalsinerte produkt avkjoles hurtig. D&t er en forutsetning for gjennomforbarheten av denne fremgangsmåte at råstoffblandingens siliciumdioxydinnhold er slik avpasset at det er tilstrekkelig til å binde det ved omset-ningen frigjorte kalsiumoxyd. På grunn av blandingens hoye siliciumdioxydinnhold som i alminnelighet er over 7%, kan det ved de for en sterk oppslutning nodvendige temperaturer oppstå forstyrrelser ved passeringen gjennom ovnen på grunn av sammensmeltninger som forer til en utilstrekkelig f jernel.se av fluor og dermed til en nedsatt opploselighet i sitronsyre for sinterproduktets fosforsyreinnhold. Det er en videre ulempe ved denne fremgangsmåte at bare en rask av-kjoling av det kalsinerte produkt kan hindre at det ved kalsineringen dannede, lett sitronsyreopploselige a-trikalsiumfosfat går over til den som ejodning mindre virksomme p-form. that approx. is added to raw phosphate. 0.5-^% sodium in the form of primary or secondary sodium orthophosphate, corresponding to 1-2 mol of sodium per moles of fluoride-bound calcium, and this mixture is calcined in the presence of steam at a temperature above 1150°C, and the calcined product is cooled rapidly. D&t is a prerequisite for the feasibility of this method that the silicon dioxide content of the raw material mixture is adjusted in such a way that it is sufficient to bind the calcium oxide released during the reaction. Due to the high silicon dioxide content of the mixture, which is generally above 7%, at the temperatures required for a strong fusion, disturbances may occur during the passage through the furnace due to fusions which lead to an insufficient removal of fluorine and thus to a reduced solubility in citric acid for the sinter product's phosphoric acid content. A further disadvantage of this method is that only rapid cooling of the calcined product can prevent the easily citric acid-soluble a-tricalcium phosphate formed during the calcination from changing to the p-form, which is less effective as iodine.
Det er hittil alltid blitt hevdet at det må være tilstede en v-iss minstemengde av siliciumdioxyd i råstoffblandingene for å Until now, it has always been claimed that there must be a certain minimum amount of silicon dioxide in the raw material mixtures in order to
sikre fjernelse av fluor fra råfosfatet. Det angis også i britisk patentskrift nr. 90236I og US patentskrift nr. 29.95<1>+37 at ved et Si09-innhold av under ca. '2,5 vekt% kan fluoret ikke i tilstrekkelig grad fjernes fra råstoffblandingen.. Ifolge. dette patentskrift av-passes Ca-, Na20-, P2°5~ og Si02-innholde± slik i blandingene av råfosfat, fosforsyre og natriumcarbonat som skal kalsineres, at mol-forholdet mellom, disse be"standdeler, (Ga0+Na20-3P20^):Si02, ikke er over 1,1, fortrinnsvis mellom 0, h og 0,8. Blandingens Na20-innhold kan derved variere mellom 0,3 og 0,7 mol pr. mol P2°^ i "råfosfatet. Ved hoyere kalsineringstemperaturer kan det ved denne ensure the removal of fluorine from the raw phosphate. It is also stated in British patent document no. 90236I and US patent document no. 29.95<1>+37 that at a Si09 content of less than approx. At 2.5% by weight, the fluorine cannot be sufficiently removed from the raw material mixture. this patent document adjusts Ca-, Na20-, P2°5~ and Si02-content± such that in the mixtures of crude phosphate, phosphoric acid and sodium carbonate to be calcined, that the mole ratio between these components, (Ga0+Na20-3P20 ^):SiO2, is not over 1.1, preferably between 0.h and 0.8. The Na2O content of the mixture can therefore vary between 0.3 and 0.7 mol per mol P20^ in the "raw phosphate. At higher calcination temperatures, this can
fremgangsmåte som reg.el oppnås en god fjernelse av fluor fra rå- . fosfatet.. Det har imidlertid vist .seg. at ojpploseligheten i sitronsyre for innholdet av P2'0^ i det kalsinerte produkt kan variere sterkt og ofte er lavere enn hva som er nodvendig for at et produkt skal ha en tilstrekkelig .gjodningsvirkning. method usually achieves a good removal of fluorine from raw materials. the phosphate.. However, it has been shown. that the solubility in citric acid for the content of P2'0^ in the calcined product can vary greatly and is often lower than what is necessary for a product to have a sufficient fertilizing effect.
I Przemysl chemiczny hG/ 11 (1967)., s. 6<i>+3-6<!>+5 (se også Referatives Journal 13 (II) Moskva av 25. juni 1968, ref. nr.l3L 198, s. 26), angis det" at avfluoreringsforsok med marokkansk, fosforitt i laboratorieskala har vist at optimale, resultater fås. ved l<L>fOO°C under tilsetning av h- 6% Si.Op, 5-6% natriumcarbonat og. 7,5-10% H^PO^ (6'5%-ig). ' Det ved hurtig.avkjoling erholdte produkt består' da hovedsakelig av a-Ca^ (PO^^ og en liten mengde av en fast opplosning av •CaNaPO^ i Ca^CPO^^ med-en struktur, av typen a-CaNaPO^. In Przemysl chemiczny hG/ 11 (1967)., pp. 6<i>+3-6<!>+5 (see also Referatives Journal 13 (II) Moscow of June 25, 1968, ref. no.l3L 198, p . 26), it is stated" that defluorination experiments with Moroccan phosphorite on a laboratory scale have shown that optimal results are obtained at l<L>fOO°C with the addition of h- 6% Si.Op, 5-6% sodium carbonate and. 7 .5-10% H^PO^ (6'5%-ig). The product obtained by rapid cooling then consists mainly of a-Ca^ (PO^^ and a small amount of a solid solution of •CaNaPO ^ in Ca^CPO^^ with-a structure, of the type a-CaNaPO^.
Den angitte hbye P20^-opploselighet kunne bare oppnås i nærvær av store mengder vanndamp (80 ml H20/5 g prove). I stor målestokk lar det seg ikke gjore okonomisk å realisere anvendelsen av slike vanndampmengder, og en teknisk prosess forer derfor'alltid til produkter med en vesentlige lavere P2Cy-oppl6selighet. The stated hbye P20^ solubility could only be achieved in the presence of large amounts of water vapor (80 ml H20/5 g sample). On a large scale, it is not economically feasible to realize the use of such amounts of water vapour, and a technical process therefore always leads to products with a significantly lower P2Cy solubility.
Den i tidsskriftet Chem. Age India 18, nr. 11 s. 8^-1-8^2 The one in the journal Chem. Age India 18, No. 11 pp. 8^-1-8^2
(1967), angitte analyseverdi for et handelsprodukt med'93,7% P2°5~ opploselighet for et fluorinnhold på 0,08% viser at det innen teknikken ikke fås slike ekstremt hoye opploseligheter som"ved laboratorieforsok. Det fremgår dessuten av analyseverdiéne at det i den senere tid også er blitt fremstilt kalsinerte fosfater i ' nærvær av over h vekt% Si02. (1967), indicated analysis value for a commercial product with '93.7% P2°5~ solubility for a fluorine content of 0.08% shows that such extremely high solubilities as "in laboratory experiments" are not obtained within the technique. It also appears from the analysis values that in recent times, calcined phosphates have also been produced in the presence of over h% by weight of SiO2.
Det har nu i motsetning til den hittil gjeldende oppfatning vist seg at nettopp ved anvendelse av siliciumdioxydfrie råfosfater eller slike som har et Si02-innhold av ikke over ca0 2 vekt%, kan det oppnås kalsinerte fosfater med en hoy P20^-opplb'selighet i sitronsyreopplosning. Det har hittil vært antatt at ved fremstilling av kalsinerte fosfater med lavt fluorinnhold ved kalsinering av blandinger av råfosfat, fosforsyre og en natriumoxyddannende forbindelse ved temperaturer over ca. 1200°C i nærvær av vanndamp måtte et visst Si02-innhold ikke underskrides. I dé kjente patentskrifter og publikasjoner'er det blitt angitt at det må opprettholdes et innhold på' 3-6% Si02 i råmatérialblandingen når fremgangsmåten, utfores. Det har imidlertid nu vist seg at ved å bestemme kjeglekollapspunktene ifolge Seger for kalsinerte produkter fremstilt ved bruk av■utgangsblandinger av råfosfater med et. Si02-innhold på 3,1 og 0,<>>+, kunne det .'fastslås at produktet med et opprinnelig S102-innhold på hadde et 20-<l>+0°C hoyer.e kjeglekollapspunkt enn produktet med.et opprinnelig Si09-innhold på 3?1% . ' Da visse temperaturvariasjoner lett kan-oppstå It has now been shown, in contrast to the hitherto current opinion, that precisely by using silicon dioxide-free raw phosphates or those that have a SiO2 content of no more than approx. 2% by weight, calcined phosphates can be obtained with a high P20^ solubility in citric acid solution. It has so far been assumed that in the production of calcined phosphates with a low fluorine content by calcining mixtures of raw phosphate, phosphoric acid and a sodium oxide-forming compound at temperatures above approx. 1200°C in the presence of water vapour, a certain SiO2 content must not be exceeded. In the known patents and publications, it has been stated that a content of 3-6% SiO2 must be maintained in the raw material mixture when the method is carried out. However, it has now been shown that by determining the cone collapse points according to Seger for calcined products produced using ■starting mixtures of crude phosphates with a. SiO2 content of 3.1 and 0.<>>+, it could be determined that the product with an original S102 content had a 20-<l>+0°C higher cone collapse point than the product with an original Si09 content of 3.1%. ' As certain temperature variations can easily occur
i en roterovn, er det. sterkt fordelaktig at reaksjonstemperaturen og smeltepunktet ligger så langt fra hverandre som mulig. Derved er det gitt, som også vist i de nedenstående eksempler, at det fås en bedre reaksjansforing når det anvendes råfosfater med et lavest mulig Si02-innhold. Ved anvendelse av disse råfosfater med lavt siliciumdioxydinnhold kan det lett oppnås et kalsinert fosfat med formelen Ca^'(POl4_)2* CaNaPO^ som .har et lavt fluorinnhold og en hoy opploselighet i sitronsyre dersom den råstoffblanding av råfosfat, fosforsyre og alkalioxyddannende forbindelse som skal. kalsineres," har et. slikt blandingsforhold at sluttproduktet får et molforhold CaO:Na20:P20^ av 8:1:3.' Den mengde P2Q^ som må tilsettes, er som regel ikke over ca. 30 vekt% av- det samlede P20^-innhold. Et overskudd eller underskudd av P20^ i forhold til mengden ifolge den ovenfor angitte formel gjor imidlertid det kalsinerte produkts opploselighet i sitronsyre alltid dårligere. in a rotary kiln, that is. strongly advantageous that the reaction temperature and the melting point are as far apart as possible. This ensures, as also shown in the examples below, that a better reaction lining is obtained when raw phosphates with the lowest possible SiO2 content are used. By using these raw phosphates with a low silicon dioxide content, a calcined phosphate with the formula Ca^'(POl4_)2* CaNaPO^ can easily be obtained, which has a low fluorine content and a high solubility in citric acid if the raw material mixture of raw phosphate, phosphoric acid and alkali oxide-forming compound which shall. is calcined," has such a mixing ratio that the final product has a molar ratio CaO:Na20:P20^ of 8:1:3.' The amount of P2Q^ that must be added is, as a rule, not more than about 30% by weight of the total P20^ content. citric acid always worse.
Det kalsinerte produkts fluorinnhold er i det vesentlige av-hengig av hastigheten som råstoffblandingen fores gj-ennom roterovnen med, og av kalsineringstemperaturene. Dersom temperaturen under kalsineringen ikke er over ca. 1<1>+00°C, har sluttproduktet" et fluorinnhold av 0,2 -. Ved hoyere temperaturer kan det oppnås fluorinnhold av under 0, 1%. Opploseligheten i sitronsyre av P20^-innholdet i de kalsinerte produkter er imidlertid alltid over 90% The fluorine content of the calcined product essentially depends on the speed with which the raw material mixture is fed through the rotary kiln, and on the calcination temperatures. If the temperature during calcination is not above approx. 1<1>+00°C, the end product" has a fluorine content of 0.2 -. At higher temperatures, a fluorine content of less than 0.1% can be achieved. However, the solubility in citric acid of the P20^ content in the calcined products is always above 90%
og kan ved sterk fjernelse av fluor være inntil over 99%. and with strong removal of fluorine can be up to over 99%.
Den på grunn av~ ovnens oljebrenner dannede vannmengde i avgassen er som regel tilstrekkelig til å fordampe fluoret fra fosfatet. Det foretrekkes imidlertid, å innfore ytterligere noe vanndamp i ovnen slik at avgassene får et vanninnhold av 10-18 volum%. Det er derfor en fordel, ved foreliggende fremgangsmåte- at det allerede ved"forholdsvis lave kalsineringstemperaturer kan fremstilles for g-jodning- egnede kalsinerte- produkter hvori, fluorinn-holdet ikke spiller noen spesiell rolle, men hvis opploselighet i en 2% sitronsyreopplosning.imidlertid må være over 3P%, hvorved oppnås vesentlige besparelser av- oppvarmings- og driftsomkostningene. Det er imidlertid på den annen side også mulig å fremstille hoy-verdig dyreforfosfat ved en egnet gjennomføring av kalsineringen. The amount of water produced in the exhaust gas due to the furnace's oil burner is usually sufficient to evaporate the fluorine from the phosphate. However, it is preferred to introduce some additional water vapor into the oven so that the exhaust gases have a water content of 10-18% by volume. It is therefore an advantage, with the present method, that already at relatively low calcination temperatures calcined products suitable for g-iodination can be produced in which the fluorine content does not play any particular role, but if solubility in a 2% citric acid solution. however must be above 3P%, whereby significant savings are achieved in heating and operating costs.However, on the other hand, it is also possible to produce high-quality animal phosphate by suitable execution of the calcination.
De't er- avg jorends. for fremgangsmåters gjennomfbrbarhot at SlG^-innholdet i -råfosfatet er under 2%. Ved anvendelse av disse They are - avg jorends. for the feasibility of the process, the SlG content in the raw phosphate is below 2%. When using these
råfosfater kan råmaterialblandingen'kalsineres i en teknisk roter-'ovn ved temperaturer inntil ca. 1550°C uten. nevneverdige ytre- for-andringer eller forstyrrelser. Tilsetningen av fosforsyre eller en raw phosphates, the raw material mixture can be calcined in a technical rotary kiln at temperatures up to approx. 1550°C without. significant external changes or disturbances. The addition of phosphoric acid or a
Na20-bærer hhv. av et tilsvarende na triumf osf a-t til råfosfatet kan gjores i et hvilket som helst egnet blandeapparat. Som Na20-bærer er natriumcarbonat og/eller konsentrerte natriumhyd-roxydopplos-ninger spesielt egnede.' De tilforte materialer gjor at råmaterialblandingen lett kan.granuleres. Ved å anvende det riktige vanninnhold dannes ca. 2-12 mm store, stabile granulater, som etter tdrking' er porose og motstandsdyktige overfor gnidning. Disse korns storrelse forandres ikke vesentlig under kalsineringen, og de kan deretter lett gjores. mindre og"' males. Hvis derimot innholdet av Na20 carrier or of a corresponding na triumf etc. a-t to the crude phosphate can be made in any suitable mixing apparatus. As Na2O carrier, sodium carbonate and/or concentrated sodium hydroxide solutions are particularly suitable. The added materials mean that the raw material mixture can be easily granulated. By using the correct water content, approx. 2-12 mm large, stable granules, which after drying are porous and resistant to rubbing. The size of these grains does not change significantly during calcination, and they can then be easily made. less and"' are painted. If, on the other hand, the content of
SiOv-) i disse blandinger bkes ved tilsetning av sand, som det av og til er blitt' foreslått, er produktet hhv.- blandingen tilbøyelig til å danne klumper og de fryktede ringer på ovnsveggen. Dette forer til en utilstrekkelig oppslutning av blandingen og en mangelfull P20^-o.pplbselighet i sitronsyre. De ved kalsineringen oppnådde produkter er i tillegg for det meste hårde- og vanskelige å gjore mindre. SiOv-) in these mixtures is baked by the addition of sand, as has occasionally been suggested, the product or mixture is prone to forming lumps and the dreaded rings on the furnace wall. This leads to an insufficient digestion of the mixture and a deficient P20^ solubility in citric acid. In addition, the products obtained during calcination are mostly hard and difficult to reduce.
På grunn av den forstyrrelsesfrie foring av råstoffblandingen gjennom roterovnen fås dessuten en god brenselutnyttelse. Avgassene kommer ut' av roterovnen med en forholdsvis lav temperatur, dvs.. 600-90a°C^ fortrinnsvis' 700-800°C. De inneholder det ved de angitte arbeidsbetingelser avdrevne fluor hovedsakelig i form av hydrogenfluorid som, for gassene forés bort gjennom skorsteinen, absorberes på egnet-måte, f.eks-.- ved vasking med vann. Da andelen av SiF^ i avgassen er meget lav i forhold til ved de kjente fremgangsmåter på grunn av det lave Sf09-innhold i råfosfatet, er det betraktelig lettere å opparbeide denne absorbsjonsopplbsning hhv. absorbsjonsmidlet til brukbare fluorforbindelser enn ved tilstede-værelse av storre SiF)+-mengder. Støvmengden i avgassen er lav fordi produktene er. i granulert form. Due to the undisturbed feeding of the raw material mixture through the rotary kiln, good fuel utilization is also achieved. The exhaust gases come out of the rotary kiln at a relatively low temperature, i.e. 600-90°C, preferably 700-800°C. They contain the fluorine removed under the specified working conditions mainly in the form of hydrogen fluoride which, as the gases are carried away through the chimney, is absorbed in a suitable way, for example by washing with water. As the proportion of SiF^ in the exhaust gas is very low compared to the known methods due to the low SfO9 content in the raw phosphate, it is considerably easier to work up this absorption solution or the absorbent to usable fluorine compounds than in the presence of larger amounts of SiF)+. The amount of dust in the exhaust gas is low because the products are in granulated form.
Under kalsineringen forflyktiges ved siden av fluorforbindelser også alltid mer eller mindre små mengder av natriumforbindelser, f.eks. i form av natriumsulfat. Disse forbindelser dannes under ovnsforingen ved omsetning av det innforte natriumoxyd med bestand-deler av råfosfatet og brenseloljen, hovedsakelig svovel. Det har vist seg nyttig å utjevne disse tap ved å anvende et overskudd av Nap_0 i råmaterialblandingen. Da den absolutte andel av Na20 i produktet med formelen Ca^ iPO^)^* CaNaPO^ er forholdsvis liten, men på den annen side sikkerhetsfaktoren ikke må settes for lavt, anvendes det fortrinnsvis ét Na20-overskudd av 5-25%. De vanlige bi-bestanddeler i råfosfatet (Fe20^, A120^, Si02) behover ved den enkle beregning for råstoffbiandingen ikke å tas i betraktning, og det er grunn til spesielt å fremheve dette. During the calcination, in addition to fluorine compounds, more or less small amounts of sodium compounds, e.g. in the form of sodium sulfate. These compounds are formed under the furnace lining by reaction of the introduced sodium oxide with components of the crude phosphate and the fuel oil, mainly sulphur. It has proved useful to balance these losses by using an excess of Nap_0 in the raw material mixture. As the absolute proportion of Na2O in the product with the formula Ca^ iPO^)^* CaNaPO^ is relatively small, but on the other hand the safety factor must not be set too low, a Na2O excess of 5-25% is preferably used. The usual by-constituents in the raw phosphate (Fe20^, A120^, Si02) do not need to be taken into account in the simple calculation for the raw material combination, and there is reason to emphasize this in particular.
Det i form av porose korn fremstilte kalsinerte produkt som ikke behover å bråkjbles, inneholder som regel over h2% P2°5<*> ^orn vist ved rontgenanalyse.har produktet en slags spesifikk struktur som adskiller seg særpreget fra a-trikalsiumfosfåtets. For sammen-lignings skyld er de viktigste rbntgeninterferenslinjer angitt: The calcined product produced in the form of porous grains, which does not need to be fractionated, usually contains more than h2% P2°5<*> ^orn shown by X-ray analysis. The product has a kind of specific structure that differs distinctively from that of a-tricalcium phosphate. For the sake of comparison, the most important X-ray interference lines are indicated:
Fremstillingen av råfosfatet med lavt fluorinnhold utfores kontinuerlig. Etter avkjoligen males det ferdige materiale og kan lagres uten spesielle forsiktighetsregler. Da det ikke er hygro-skopisk, er det ikke tilboyelig til å bake .sammen. Det kan av-hengig av fremstillingen anvendes som fosfatgjbdning eller som fos-fatmateriale for dyreffjr.... The production of the raw phosphate with a low fluorine content is carried out continuously. After cooling, the finished material is ground and can be stored without special precautions. As it is not hygroscopic, it is not prone to baking together. Depending on the production, it can be used as phosphate fertilizer or as phosphate material for animal fur....
Eksempel 1 Example 1
Marokko-fosfat, fosforsyre og '50% natronlut ble kontinuerlig satt til"et blandeapparat. Mengdeforholdene ble avpasset slik at Moroccan phosphate, phosphoric acid and 50% caustic soda were continuously added to a mixer. The quantity ratios were adjusted so that
ået pr. 1000 kg Marokko-fosfat som-inneholdt 3^,8% P2°ij> 52,5%..CaO, 0,8% Si02 og <l>+,2% F, var 150 kg- P20^ i form av fosforsyre og 82, h kg Na2-0 i form av natronlut. Materialblandingen ble fra blande- the stream per 1000 kg Morocco phosphate containing 3^.8% P2°ij> 52.5%..CaO, 0.8% SiO2 and <l>+.2% F, was 150 kg- P20^ in the form of phosphoric acid and 82, h kg Na2-0 in the form of caustic soda. The material mixture was from mixing
apparatet overfort til en granulattorker hvor 2-10 mm store, torre granulater ble dannet. Deretter ble granulatet tilfort en roterovn hvori det ble kalsinert i motstrdm inntil en hoyeste temperatur 'av 1^70 C i nærvær av vanndamp. Avgasstemperaturen var 750°C og av-gassens vanninnhold 13 volum-. Materialet rislet gjennom ovnen uten sammenklebning eller avsetninger på veggen slik at det kom ut med praktisk talt samme kornstorrelse som det ble tilfort med. Det oppnådde kalsinerte fosfat inneholdt M+,3% P20^°S 0,1% F„ Inntil 99,5% av P20^-innholdet var opploselig i en 2% sitronsyreopplosning. the apparatus was transferred to a granulate drier where 2-10 mm large, dry granules were formed. The granulate was then fed to a rotary kiln in which it was calcined in a counter current up to a highest temperature of 170 C in the presence of water vapour. The exhaust gas temperature was 750°C and the water content of the exhaust gas 13 vol. The material trickled through the furnace without sticking or deposits on the wall so that it came out with practically the same grain size as it was fed. The obtained calcined phosphate contained M+.3% P20^°S 0.1% F„ Until 99.5% of the P20^ content was soluble in a 2% citric acid solution.
Eksempel 2 Example 2
Arbeidsbetingelsene ifdlge eksempel 1 ble forandret ved at den granulerte råmaterialblanding ble kalsinert med en hoyere til-for selshastighet i den samme roterovn ved en hoyeste temperatur av 1<1>+00°C uten at det ble dannet avsetninger og klumper etc. Sluttproduktet inneholdt 0,38% F, og 92,8% av dets innhold av P20^ v^r opploselig i en 2% sitronsyreopplosning. The working conditions according to example 1 were changed in that the granulated raw material mixture was calcined at a higher feed rate in the same rotary kiln at a highest temperature of 1<1>+00°C without the formation of deposits and lumps etc. The end product contained 0 .38% F, and 92.8% of its P20^ content is soluble in a 2% citric acid solution.
Eksemne! 3 Eczema! 3
En råmaterialblanding av et vest-afrikansk råfosfat, fosforsyre og 50% natrronlut ble tilfort til det sammen anlegg sorn i eksempel 1 og bearbeidet på analog måte. Det ble pr. 1000 kg fos-fatmineral med 37,2% P20^,.50,5% CaO, 1,9% Si02 og 3,7% F anvendt 70 kg Na20 i form av natronlut og 108,5 kg P20^ i form av fosforsyre. Den granulerte og torkede blanding ble kalsinert i roterovnen til en hoyeste temperatur av 1^-90 C uten at det forekom klump-dannelse eller avsetninger. Det ble fra brennersiden tilfort vanndamp slik at avgassen som ved tilforselsenden hadde en temperatur av 770°C, inneholdt 15 volum% vann. Ferdigproduktet inneholdt <i>+3,1% P20^ og 0,09% F. P20^-opploseligheten i sitronsyre var 97,8%. A raw material mixture of a West African raw phosphate, phosphoric acid and 50% caustic soda was added to the combined plant in Example 1 and processed in an analogous manner. It was per 1000 kg phosphate mineral with 37.2% P20^, 50.5% CaO, 1.9% SiO2 and 3.7% F used 70 kg Na20 in the form of caustic soda and 108.5 kg P20^ in the form of phosphoric acid . The granulated and dried mixture was calcined in the rotary kiln to a maximum temperature of 1^-90 C without lump formation or deposits occurring. Water vapor was added from the burner side so that the exhaust gas, which at the supply end had a temperature of 770°C, contained 15% water by volume. The finished product contained <i>+3.1% P20^ and 0.09% F. The P20^ solubility in citric acid was 97.8%.
Eksempel h Example h
Den samme granulerte råmaterialblanding' som i eksempel 3 ble ved en hoyere tilforselshastighet og en hoyeste' kalsineringstem-' peratur av 1390°C overfort uten dannelse av avsetninger til et kalsinert produkt med 0,^% F og en 92,5% P20^-opploselighet i sitron-syreopplosnin<g>,. The same granulated raw material mixture as in Example 3 was, at a higher feed rate and a highest calcination temperature of 1390°C, transferred without the formation of deposits to a calcined product with 0.5% F and a 92.5% P 2 O solubility in citric acid solution<g>,.
Eksempel 5 Example 5
En blanding av Kola-apatitt, fosforsyre og natriumcarbonat ble på analog måte som i eksempel 1 granulert, torket og kontinuerlig tilfort til en roterovn for kalsinering. Kola-apatitten inneholdt 39,1% PpOj, 52,5% CaO, 1,6% Si02 og 3,2% F. Det-ble pr. 1000 kg apatitt anvendt fosforsyre i en mengde tilsvarende 107,9 kg P2°j og en natriumcarbonatmengde.tilsvarende 85,5 kg Na20. De små korn passerte gjennom kalsineringsovnen uten .at det-ble dannet klumper eller avsetninger på veggene. Den hoyeste kalsinerings.tempsratur var 1500°C og avgasstemperaturen 780°C. Ved innsprøyting av vann ble vanninnholdet i avgassen ca. lh volum%. Analyser viste at det kalsinerte fosfat inneholdt ^3,5% P20^ og 0,11% F. Dets Pg<O>^<->opp<->loselighet i sitronsyre ble fastslått til 97%. A mixture of Kola apatite, phosphoric acid and sodium carbonate was granulated, dried and continuously added to a rotary kiln for calcination in an analogous manner to example 1. The kola apatite contained 39.1% PpOj, 52.5% CaO, 1.6% SiO2 and 3.2% F. It was per 1000 kg of apatite used phosphoric acid in an amount corresponding to 107.9 kg P2°j and a sodium carbonate amount corresponding to 85.5 kg Na20. The small grains passed through the calcining furnace without forming lumps or deposits on the walls. The highest calcination temperature was 1500°C and the exhaust gas temperature 780°C. When water was injected, the water content in the exhaust gas was approx. lh volume%. Analyzes showed that the calcined phosphate contained ^3.5% P2O^ and 0.11% F. Its Pg<O>^<->up<->solubility in citric acid was determined to be 97%.
Eksempel 6 Example 6
Råmaterialproduktet ifolge eksempel 5 ble ved oket tilsetnings-hastighet og nedsatt kalsineringstemperatur avfluorert inntil et F-innhold av 0,33%. Det kalsinerte fosfat hadde en P20^-opploselighet i sitronsyreopplosning av 96,3%. The raw material product according to example 5 was defluorinated to an F content of 0.33% by increasing the addition rate and decreasing the calcination temperature. The calcined phosphate had a P 2 O 3 solubility in citric acid solution of 96.3%.
Claims (2)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
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DE19681816660 DE1816660C3 (en) | 1968-12-23 | Process for the production of a low-fluorine calcined phosphate |
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NO130638B true NO130638B (en) | 1974-10-07 |
NO130638C NO130638C (en) | 1975-01-15 |
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NO695068A NO130638C (en) | 1968-12-23 | 1969-12-22 |
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BE (1) | BE743554A (en) |
DK (1) | DK132111C (en) |
ES (1) | ES374805A1 (en) |
FI (1) | FI52839C (en) |
FR (1) | FR2026878A1 (en) |
NL (1) | NL159644C (en) |
NO (1) | NO130638C (en) |
PL (1) | PL93573B1 (en) |
SE (1) | SE357188B (en) |
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DE2709016C3 (en) * | 1977-03-02 | 1980-01-10 | Kali-Chemie Ag, 3000 Hannover | Process for the production of an alkaline calcined phosphate fertilizer |
FR2446254A1 (en) * | 1979-01-15 | 1980-08-08 | Ugine Kuhlmann | DEFLUORED NATURAL CALCIUM PHOSPHATE FOR ANIMAL FEED |
-
1969
- 1969-12-17 FI FI693671A patent/FI52839C/en active
- 1969-12-17 FR FR6943811A patent/FR2026878A1/en not_active Withdrawn
- 1969-12-18 NL NL6919008.A patent/NL159644C/en not_active IP Right Cessation
- 1969-12-22 PL PL1969137752A patent/PL93573B1/pl unknown
- 1969-12-22 DK DK678869A patent/DK132111C/en active
- 1969-12-22 NO NO695068A patent/NO130638C/no unknown
- 1969-12-22 ES ES374805A patent/ES374805A1/en not_active Expired
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- 1969-12-22 BE BE743554A patent/BE743554A/fr unknown
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BE743554A (en) | 1970-02-27 |
SE357188B (en) | 1973-06-18 |
DK132111C (en) | 1976-03-22 |
FI52839B (en) | 1977-08-31 |
NO130638C (en) | 1975-01-15 |
NL159644B (en) | 1979-03-15 |
FI52839C (en) | 1977-12-12 |
FR2026878A1 (en) | 1970-09-25 |
NL6919008A (en) | 1970-06-25 |
NL159644C (en) | 1980-03-17 |
ES374805A1 (en) | 1972-01-16 |
DE1816660B2 (en) | 1972-12-28 |
DK132111B (en) | 1975-10-27 |
PL93573B1 (en) | 1977-06-30 |
DE1816660A1 (en) | 1970-09-24 |
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